Detonator crimping device



Dec. 2 l ,1 954 G. R. DIXON DETONATOR CRIMPING DEVICE Filed June 24, 1949 INVENTORI GLENN R. DIXON ATTORNEY.

United States Patent DETONATOR CRIMPING DEVICE This invention pertains to a device for crimping blasting caps or detonators. Such a blasting cap or detonator is usually provided with a thin-walled outer metallic shell, into the end of which the fuse or bridge plug with lead wires is inserted. The shell wall is then crimped into the plug to seal the shell.

Heretofore ditliculty has been encountered in obtain ng a good seal in crimping articles of this kind. Crimping devices which simply apply pressure from opposlte sides, such as some plier-like hand tools, often leave discontinuities in the crimp, while those which rotate the shell to crimp it all around also twist the lead wires of the blasting cap, which is also objectionable.

One of the objects of this invention, therefore, is to provide a device which will elfect a uniform and continuous crimp all around the shell without twisting the leads.

Another object is to provide a device of this character with'mechanism whereby a crimp wheel may be operated so as to roll about the article to be crimped, substantially without slippage and while the article remains stationary.

Further objects will appear from the following description, in which will be set forth an illustrative embodiment of this invention. It is to be understood, however, that this invention is susceptible of various embodiments, w thin the scope of the appended claims, without departlng from the principle or spirit of the invention.

In accordance with this invention, generally stated, the blasting cap to be crimped is inserted in a socket provided therefor in a crimping head. Said head is then rotated on a stationary pivot aligned with the blasting cap, so that the head rotates about the axis of the cap. A crimp wheel having one or more crimping beads is mounted on said head and geared to the stationary pivot in such a way that, as the head turns, the crimp wheel turns relatively thereto at just the right speed to make it roll on the blasting cap practically without slippage. Thus the crimp is made by simple rolling action of the crimp wheel.

A practical embodiment of this invention is illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view of a crimping machine embodying this invention;

Figure 2 is a perspective view, partly in section, of the crimping head;

Figure 3 is a plan view of the crimping head;

Figure 4 is a partial section on line 4-4 of Figure 1;

Figure 5 is a perspective view of a holder for the blasting cap; and

Figure 6 is a side view of a crimped cap.

Referring now to the drawings, 1 designates the upper, and 2 the lower plate of a supporting base. These plates may be held in proper spaced relation by suitable spacers or legs 3. A crimping head 4 is mounted between the plates 1 and 2 for rotation on a vertical pivot 5. The pivot 5 may be fixed in the plate 2 by a set screw 6 or other suitable means. The plate 1 may be provided with an opening 7, within which the head 4 may turn, said opening being closed by a cover plate 8. Aligned holes 9 and 10 in the cover plate 8 and the head 4, respectively, provide a socket for receiving the blasting cap 11 to be crimped.

The holes 9 and 10 are also aligned with the axis of the pivot 5, the upper end of which has fixed thereon a pinion 12. Suitably journaled in the head 4 is a vertical shaft 13 carrying at its lower end a gear 14 meshing with the pinion l2, and at its upper end a crimp wheel 15 having one or more crimping beads 16, there being two in the ice embodiment illustrated. The crimp wheel 15 isformed with a flat 17, which when turned adjacent the holes 9 and 10, clears said holes for the insertion of the blasting cap. The head 4 also carries a pair of backing rolls 18 positioned to support the cap against the crimping pressure of the wheel 15.

Fixed to the underside of the head 4, as by dowels 19 or otherwise, is a gear 20. Both the gear 20 and the head 4 are loose on the pivot 5, so that they may rotate thereon. The gear 20 meshes with another gear 21 suitably journaled in the plates 1 and 2, the latter gear being provided with a handle or other manipulating element 22.

The pitch diameter of the pinion 12 is made substantially equal to the diameter of the shell of the cap 11, and the pitch diameter of the gear 14 is made equal to the root diameter (between the beads 16) of the wheel 15. Accordingly, as the head 4 turns on the pivot 5, the movement of the root portion of the wheel 15 about its axis will be the same as if it were rolling on the shell 11. Thus there will be no slippage between the two and no tendency to turn the shell. However, as the deformation forces involved in the crimping action may not act in a direction through the axis of the shell 11, there may be some tendency to rotate the shell. It has been found that such tendency may be overcome to a practical extent by roughening the edges of the beads 16, as by knurling or otherwise. A manipulating grip 23 may be provided for handling the detonator. The latter is inserted in the jaws 24 and then inserted in the opening 9. A hole 25 in the grip is engageable with a pin 26 on the plate 1 to keep the grip in position. By slipping the detonator up or down in the jaws 24, its position with reference to the crimp wheel may be varied so that the crimp may be formed at any desired point along the length of the detonator.

In the operation of this device, the wheel 15 is rotated to bring the flat 17 adjacent the socket holes 9 and 10, and the blasting cap 11 is inserted as shown in Figure 4. The handle 22 is then manipulated to rotate the head 4. Such rotation causes the gear 14 to roll on the pinion 12 and this causes the crimp wheel 15 to roll about the shell 11. During such movement, the beads 16 indent the shell to form encircling grooves 27, as shown in Figure 6, while the shell is supported against the crimping pressure by the backing rolls 18. The indented portions 27 are pressed into the sealing plug within the shell to make a water-tight seal. After one revolution of the wheel 15, the flat 17 is again brought adjacent the socket holes and the crimped cap may be removed. If desired, stops for the handle 22 may be positioned to engage the same when the fiat 17 is in proper position.

It will be seen that this invention provides a simple tool for making an effective seal in a blasting cap or detonator by insuring a continuous crimp entirely around the shell. The diameter of the wheel 15 is made such that the circumferential length of the beads 16 is greater than the circumference of the shell 11, so that they are long enough to pass more than once around the shell. This insures a complete crimp. As the cap 11 remains stationary during the crimping operation, it may be crimped into an adjunct plug (with lead wires attached) without twisting the lead wires.

While one complete embodiment of the invention has been disclosed in detail, it is not to be understood that the invention is limited to that embodiment. On the contrary, the crimping device may be modified and adapted in sundry respects without departing from the spirit of the invention or the scope of the appended claims wherein the word detonator is used in the generic sense as embracing both electric and fuse-initiated blasting caps.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

l. A device for crimping detonators of the character described, comprising a rotary frame having a socket adapted to receive the detonator, a crimp wheel journaled on said frame eccentrically of said socket, a shaft constituting a stationary pivot for said frame axially aligned with the detonator in said socket, and gearing between said shaft and said wheel positively driving the latter in rotation and causing the latter to roll on the detonator when said frame is rotated relative to said shaft.

- described, comprising arotary 3 i 2. A device for crimping detonators of the character frame having a socket adapted to receive the detonator, a crimp wheel journaled on said frame adjacent said socket and having a crimping bead formed with a roughened edge, a stationary, pivot for said frame aligned with. the. detonator in saidvsocket, and the gearing between saidpivot and. said Wheelpositively driving the latter in,rotation,about its axis when said, frame is rotated-.onsaidpivot,

3. A device for crimping detonators of,'the character described, comprising a; rotary frame having a, socket adapted to receive the, detonator, a crimp wheel journaled on saidframe adjacent said socket and. having a crimping bead formed with a roughened edge, astation= ary pivot for said frame aligned withthe detonator in said socket, and the gearing between said pivotand said wheel, positively driving the latter in rotation about its axis when said frame; is rotated on; said pivot, and a grip adapted to position the detonator withv reference to, said crimp wheel.

4. A device for crimping detonators of thecharacter described, comprising a rotary frame having a socket adapted to receive the detonator, a crimp wheel journaled on said frame adjacent said socket, a stationary pivot for said frame al gned with the detonatorin said socket, a pinion on said; pivot having a pitch, diameter substantially equal to the diameter of the detonator, a gear meshingwith said pinion having a pitch diameter substantially equal to the diameter of'said crimp wheel, arild 2i rigid connection between said gear andsaid crimp w ee 5, A device for crimping detonatorsof thecharacter described, comprising astatiouary-base, a frame mounted for rotation on said base and having a socket adapted to, receive the detonator, a stationary pivot for said frame fixed to said base, a pinion on said pivot aligned. with the detonator in said socket and having, a pitch diameter substantially equal to the diameter of the detonator, a crimpwheel for crimping the-detonator, a shaft for said crimp wheel journaled in said frame, a gear on said shaft meshing with said pinion and having a pitch diameter substantially equal to the diameter of said crimp wheel, and means for swinging said frame on its pivot whereby the action of said gears causessaid crimp wheel to roll on the detonator substantially without slipping.

6. A device for crimping detonators of the character described, comprising a stationary base, a frame mounted for rotation on said base and having a socket adapted to receive the detonator, astationary pivot for said frame fixed to said base, a pinion on said pivot aligned with the detonator in said socket andhaving a pitchdiameter substantially equal to the diameter of the detonator, a crimp wheel for crimping the detonator, a shaft for said crimp wheel journaled in said frame, a gear on said shaft meshing with said pinion and having a pitch diameter substantially equal to the diameter of said crimp wheel, means for supporting the detonator under the crimping pressure, and means for swinging said frame on its pivot whereby the action of said gears causes said crimp wheel to roll on the detonator substantially without slipping.

References Cited in the file of this patent. UNITED STATES PATENTS Number Name Date 147,321 Hall Feb. 10, 1874 1,190,576 Page July 11, 1916 2,295,033 Fagan Sept. 8, 1942 2,469,426 Anthony, May 10, 1949 2,490,880 Olson Dec. 13,.1949

FOREIGN PATENTS Number Country Date 7,271/32 Australia Aug. 17, 1933 

